As is generally known in the art, thermoset rubber compositions, which may also be referred to as vulcanizates, often include reinforcing fillers. These reinforcing fillers provide, among other advantages, strength and toughness to the thermoset composition.
One of the major drawbacks of reinforcing fillers is their negative impact on hysteresis. Some of the negative consequences of higher hysteresis are higher heat build up and higher energy loss. In fact, while reinforcing filler can increase storage modulus (G′), increases in G′ due to reinforcing filler are often associated with increase in tan δ. Another major draw back is their negative impact on processing. Higher filler loading is associated with high viscosity.